Messier 17
E105137
Messier 17, also known as the Omega or Swan Nebula, is a bright star-forming emission nebula located in the constellation Sagittarius.
All labels observed (5)
| Label | Occurrences |
|---|---|
| Messier 17 canonical | 8 |
| H II region M17 | 1 |
| M17 (Omega Nebula) | 1 |
| M17 star-forming region | 1 |
| Omega Nebula (M17) | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T869226 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Messier 17 Context triple: [Sagittarius, contains, Messier 17]
-
A.
Orion Nebula
The Orion Nebula is a bright, nearby stellar nursery where new stars and planetary systems are actively forming within the constellation Orion.
-
B.
Carina Nebula
The Carina Nebula is a vast, active star-forming region in the Milky Way known for its towering gas and dust pillars and dramatic young stellar clusters.
-
C.
NGC 6822
NGC 6822 is a barred irregular dwarf galaxy located in the constellation Sagittarius and is one of the nearest and best-studied galaxies outside the Milky Way.
-
D.
Messier 8
Messier 8, also known as the Lagoon Nebula, is a large, bright emission nebula and active star-forming region visible in the constellation Sagittarius.
-
E.
Open cluster NGC 6530
Open cluster NGC 6530 is a young, bright star cluster embedded in the Lagoon Nebula in the constellation Sagittarius, serving as a prominent site of active star formation within the Milky Way.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Messier 17 Target entity description: Messier 17, also known as the Omega or Swan Nebula, is a bright star-forming emission nebula located in the constellation Sagittarius.
-
A.
Orion Nebula
The Orion Nebula is a bright, nearby stellar nursery where new stars and planetary systems are actively forming within the constellation Orion.
-
B.
Carina Nebula
The Carina Nebula is a vast, active star-forming region in the Milky Way known for its towering gas and dust pillars and dramatic young stellar clusters.
-
C.
NGC 6822
NGC 6822 is a barred irregular dwarf galaxy located in the constellation Sagittarius and is one of the nearest and best-studied galaxies outside the Milky Way.
-
D.
Messier 8
Messier 8, also known as the Lagoon Nebula, is a large, bright emission nebula and active star-forming region visible in the constellation Sagittarius.
-
E.
Open cluster NGC 6530
Open cluster NGC 6530 is a young, bright star cluster embedded in the Lagoon Nebula in the constellation Sagittarius, serving as a prominent site of active star formation within the Milky Way.
- F. None of above. chosen
Statements (47)
| Predicate | Object |
|---|---|
| instanceOf |
H II region
ⓘ
Messier object ⓘ NGC object ⓘ emission nebula ⓘ star-forming region ⓘ |
| addedToMessierCatalogueBy | Charles Messier ⓘ |
| alsoKnownAs |
Checkmark Nebula
ⓘ
Horseshoe Nebula ⓘ
linked to:
Swan Nebula
Omega Nebula ⓘ Swan Nebula ⓘ |
| angularSize | 11 arcminutes × 6 arcminutes ⓘ |
| apparentMagnitudeV | 6.0 ⓘ |
| bestSeenIn |
binoculars
ⓘ
small telescopes ⓘ summer ⓘ |
| catalogNumber |
M17
ⓘ
NGC 6618 ⓘ |
| contains |
dust lanes
ⓘ
molecular clouds ⓘ open star cluster ⓘ young massive stars ⓘ |
| declination | −16° 11′ ⓘ |
| discoveredBy | Philippe Loys de Chéseaux ⓘ |
| discoveryYear | 1745 ⓘ |
| distanceFromEarth |
about 1.6 kiloparsecs
ⓘ
about 5,000 light-years ⓘ |
| dominantEmissionLines | hydrogen alpha ⓘ |
| galacticLatitude | −0.7 degrees (approximate) ⓘ |
| galacticLongitude | 15.1 degrees (approximate) ⓘ |
| hasShapeAppearance |
omega-shaped
ⓘ
swan-like ⓘ |
| ionizingSource | massive O-type stars ⓘ |
| locatedIn |
Milky Way
ⓘ
Sagittarius Arm ⓘ |
| locatedInConstellation | Sagittarius ⓘ |
| locatedNear | galactic plane ⓘ |
| messierCatalogueEntryYear | 1764 ⓘ |
| observableFrom |
Northern Hemisphere
ⓘ
Southern Hemisphere ⓘ |
| partOf | a giant molecular cloud complex ⓘ |
| regionType | massive star-forming complex ⓘ |
| rightAscension | 18h 20m ⓘ |
| spectralType | H II emission ⓘ |
| starFormationActivity | intense ⓘ |
| visibleInWavelength |
infrared
ⓘ
optical ⓘ radio ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Messier 17 Description of subject: Messier 17, also known as the Omega or Swan Nebula, is a bright star-forming emission nebula located in the constellation Sagittarius.
Referenced by (12)
Full triples — surface form annotated when it differs from this entity's canonical label.
linked to: Messier 17
linked to: Messier 17
linked to: Messier 17